In recent years, digital cameras (image sensing devices) which can sense images and convert them into digital image data by simple operations have been prevalent. When an image sensed by such camera is printed and used as a photo, it is a common practice to temporarily download the sensed digital image data from a digital camera to a PC (computer), execute an image process by the PC, and output the processed image data from the PC to a color printer, thus printing an image.
By contrast, for example, a color print system, which allows a digital camera to directly transfer digital image data to a color printer without the intervention of any PC and can print it out, a so called photo direct (PD) printer in which a memory card that is mounted in a digital camera and stores sensed images can be directly mounted in the color printer and sensed images stored in the memory card can be printed, has recently been developed.
Particularly, in order to directly transfer image data from a digital camera to a printer and print the image data, demands have arisen for standardization of interface specifications between a digital camera of each manufacturer and a printer, the operation method, and the like. One proposal for standardization is a guideline for realizing a DPS (Direct Print System).
In recent digital cameras, the resolution of a sensed image becomes higher along with an increase in the resolution of a printer which prints the image and user's demands for obtaining a higher-quality image. As the image resolution increases, the image data amount also abruptly increases. If high-resolution image data is transmitted from the camera to the printer at once, some printers may not save the received data in their memories.